With that briefly infamous field in Middlesex now restored to suburban anonymity and the cadres of the Camp for Climate Action presumably considering their next move, the airwaves and news wires once again carry a depressingly familiar sound. Last week, the actress and alleged green convert Sienna Miller did the radio and television rounds, refusing to countenance the idea of reducing her air travel but advising the public to turn down their central heating. We now learn that the BBC has been planning Planet Relief, an eco-telethon set to feature tireless environmental campaigners such as Ricky Gervais and Jonathan Ross. Meanwhile, David Cameron is apparently preparing to add to the noise by returning to his own eternally confused kind of greenery.

If any credible environmentalist should be speaking the hardened language of priorities, one much-overlooked story surely deserves a lot more attention: what may soon be known as the new coal rush, and developments so at odds with the imperatives of climate change that they suggest a fast track towards irreversible disaster. The ubiquitous reduction of green politics to ethical consumerism means we'd probably rather carry on talking about cars, thermostats and lightbulbs. Faced with a resurgence that spans most of the planet, even the most righteous green activist could be forgiven for feeling powerless. No matter; what with skyrocketing gas prices and the fractious state of geopolitics, the stuff responsible for a quarter of the world's CO2 emissions is on a roll, which surely represents our biggest environmental headache of all.

China, that rapidly advancing dystopia where rivers run black and miners are killed at the rate of 5,000 a year (witness this month's coverage of the 180 trapped and probably killed in Shandong province, and the two brothers who dug their way out of a collapsed shaft near Beijing), is building an average of two coal-fired power stations a week, and in six years has doubled its annual coal production. India will construct more than 100 coal-fired plants over the next decade. Panicked by the possible policy repercussions of George Bush's departure, US power corporations are desperately pushing ahead with plans for about 150 coal-fired stations and leaning hard on presidential candidates - as evidenced by Rudy Giuliani's recent suggestion that the US should "increase our reliance on coal".

Moreover, the new coal rush is truly global: in the next five years, 37 countries - among them plenty of Kyoto signatories - will build additional coal-fired capacity, while world coal production heads towards a peak that will apparently materialise in about 25 years' time.

In Britain, with policy in part driven by EU environmental regulations that will bite in 2015, our oldest coal stations are on the way out. But with sobering historical echoes, the coal-fired power industry is also looking resurgent. If a planning decision due next month goes its way, the power giant E.ON will be on the way to building the first new UK coal-fired power station since 1974, at Kingsnorth in Kent. RWE Npower wants to follow suit with two more, in Essex and Northumberland; Scottish and Southern Energy may yet submit plans for a plant near Pontefract. Judged by the criteria of the balance sheet, who can blame them? Drax, the vast coal-fired Yorkshire plant that formed the backdrop to last year's inaugural climate camp, might be built around a single chimney that pumps out more CO2 than 103 countries, but at the last count its annual profits came in at £650m.

Perhaps most remarkably, thanks to a company called EnergyBuild, two deep coal mines will soon reopen in the Dulais and Neath valleys of south Wales, and more such projects are being mooted in the other "uneconomic" coalfields of yesteryear. By way of encouragement, what used to be called the DTI threw the Welsh scheme £3.5m from a subsidy pot which totals around £60m, in keeping with a government policy that attracts surprisingly little attention. Emissions targets, after all, are one thing, supposed security of energy supply is quite another. The recent energy white paper says as much: it talks not only about securing "the long-term future of coal-fired power generation", but the imperative "to optimise the use of our coal reserves".

There is, admittedly, accompanying material about "stimulating investment in clean coal technologies", representative of a stock line peddled not just by Whitehall and Westminster insiders, but the kind of greens who, usually thanks to an ideological antipathy to the nuclear industry, dreamily look to a future in which the black stuff's eco-credentials might miraculously be transformed. Here, no end of faith is focused on the coal industry's shiniest silver bullet: carbon capture and storage (CCS), whereby billions upon billions of tones of CO2 will one day be pumped underground.

Talk to the advocates of CCS and you soon bump up against a weird kind of public relations that somehow combines evangelistic hype with all kinds of qualifications. They cite a handful of pilot schemes (which, just to soothe green hearts, often aim at using CO2 to release untapped oil and gas reserves), though the volumes involved are for now trifling. Even on the most optimistic projections, CCS won't become viable on any convincing scale until well after 2030, and how much additional energy would be required to put the technique into worldwide practice remains a mystery. Whether it will be economically workable is another matter, not least for the countries whose room for manoeuvre is far less than that of the industrialised west. One UN study has estimated that obliging the coal-fired power industry to embrace CCS could push up the cost of the electricity it produces by anything between 40% and 90%.

Tellingly, CCS is to the mainstream environmental movement what transubstantiation is to Christianity. Friends of the Earth are CCS enthusiasts; Greenpeace see it as an illusory diversion that should be "way down anyone's list of priorities". Even some captains of the coal industry have their doubts: when I spoke earlier this year to the chief executive of Drax, her line on CCS was that "sitting here today, it's quite a challenge to say it's going to be economically attractive, and feasible, and viable".

The essential point is this. Carbon capture might have some appeal as a means of managing the emissions of a coal industry that could thereby be slowly scaled down, but it is currently being transformed into the justification for a hair-raising level of expansion. Besides, as things stand, the vast majority of the world's coal-fired newbuild - including those power stations due to be constructed in the US - will not even be CCS compatible.

So, faced by a world apparently gone coal-mad, what to do? Britain's best bet would be to make a modest stand for environmental best practice and leave King Coal and his deathly, dystopian ways well alone. You cannot badger people into recycling, composting and fretting about their footprint while prolonging the hegemony of the dirtiest fossil fuel of all. To pilfer the name of the ethical consumer's favourite indulgence, the future can't be both green and black.